Graphs To Facilitate the Computation of Patient Response to Platelet Concentrates or Antihemophiliac Concentrate B.A. MYHREAND Y. NAKASAKO From the Department of Pathofogy, U.C.L.A. School of Medicine, Harbor General Hospital Campus. Torrance, California
THE BLOOD COMPONENT THERAPY manual distributed by the American Association of Blood Banks' provides nomograms and graphs for the computing of body surface area of patients and, from this, their blood and plasma volumes. These aids allow one to avoid the mathematics required for calculating the appropriate values needed in determining dosage and patient response to platelets and Factor VIII hemophiliac globulin (AHG). However, after these values are determined, it still is necessary to calculate the estimated responses to components. We have found that many members of the house staff have difficulty with this. Therefore, we have used the formulas listed in the cited Received for publication March 17, 1976; accepted May 10, 1976.
manual' and expressed their results in graphic form (Figs. 1 and 2). For convenience, these graphs have been made of appropriate size to be duplicated and taped into the blood components manual. Figure 1 shows the theoretical response of a patient to platelet transfusions. To determine ,the correct number of platelet concentrates to be given, determine the blood volume of the patient by using Tables 3 and 4 or Table 5 in reference 1. Note this volume in the abscissa of Figure 1, choose the desired rise in platelets on the ordinate, and the intercept of the two lines indicates how many bags of platelets will be required. The response curve is calculated on each bag containing 5.5 x 10'O platelets-the minimal number required by the Bureau of Biologics, FDA (BOB).2 If one wishes to determine the
FIG. I . Platelet response curve: Shows relationship between patient's blood volume, theoretical rise in platelet count and number of bags of platelet concentrate infused.
BLMX) VOLUME , Irnl I
179 Transfusion Mar:Apr. 1977
Volume 17 Number 2
180
Transfusion Mar.-Apr. 1977
MYHRE AND NAKASAKO
280026002400-
F I G . 2. F a c t o r V I I I response curve: Shows relationship between body surface area or male’s plasma volume, desired Factor VIII level and number of Factor VIII units theoretically required to a t t a i n this response; also shows amount of cryoprecipitate bags which may achieve this volume.
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theoretical response in a patient from a given number of platelet concentrates, the procedure should be reversed. Figure 2 is used in like manner to determine responses to Factor VIII concentrate or cryoprecipitate. Again the body surface area or plasma volume are determined, after which the desired treatment line is selected. For convenience we also have included on this graph selected plasma volumes for males to simplify the use. The theoretical number of Factor VIII units needed is read from the ordinate. If cryoprecipitate is used, the center column indicates the approximate number of cryoprecipitate bags which should be used, based on a theoretical content of 90 Factor VIII units per bag. This amount is slightly less than that required by the BOB (40 units per 100 mi
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starting p l a ~ r n a ) ,but ~ represents a rather good average with a slight safety factor. We hope that these curves will further simplify the use of these blood components and will encourage physicians to compute the response of their patients in a more quantitative manner. References Myhre, B. A,, Ed.: Blood Component Therapy, 2nd ed. American Association of Blood Banks, 1975. 2. Federal Register 40:4380, 1975. 3. Federal Register 40:41799, 1975. I.
Byron A. Myhre, M.D., Ph.D., Harbor General Hospital Campus, 1000 West Carson St., Torrance, California 90509. Y. Nakasako, M.D., Harbor General Hospital Campus, Torrance, California, 90509.
THE BLOOD COMPONENT THERAPY manual distributed by the American Association of Blood Banks' provides nomograms and graphs for the computing of body surface area of patients and, from this, their blood and plasma volumes. These aids allow one to avoid the mathematics required for calculating the appropriate values needed in determining dosage and patient response to platelets and Factor VIII hemophiliac globulin (AHG). However, after these values are determined, it still is necessary to calculate the estimated responses to components. We have found that many members of the house staff have difficulty with this. Therefore, we have used the formulas listed in the cited Received for publication March 17, 1976; accepted May 10, 1976.
manual' and expressed their results in graphic form (Figs. 1 and 2). For convenience, these graphs have been made of appropriate size to be duplicated and taped into the blood components manual. Figure 1 shows the theoretical response of a patient to platelet transfusions. To determine ,the correct number of platelet concentrates to be given, determine the blood volume of the patient by using Tables 3 and 4 or Table 5 in reference 1. Note this volume in the abscissa of Figure 1, choose the desired rise in platelets on the ordinate, and the intercept of the two lines indicates how many bags of platelets will be required. The response curve is calculated on each bag containing 5.5 x 10'O platelets-the minimal number required by the Bureau of Biologics, FDA (BOB).2 If one wishes to determine the
FIG. I . Platelet response curve: Shows relationship between patient's blood volume, theoretical rise in platelet count and number of bags of platelet concentrate infused.
BLMX) VOLUME , Irnl I
179 Transfusion Mar:Apr. 1977
Volume 17 Number 2
180
Transfusion Mar.-Apr. 1977
MYHRE AND NAKASAKO
280026002400-
F I G . 2. F a c t o r V I I I response curve: Shows relationship between body surface area or male’s plasma volume, desired Factor VIII level and number of Factor VIII units theoretically required to a t t a i n this response; also shows amount of cryoprecipitate bags which may achieve this volume.
2200-
i r
2000-
: : : :1
s$ .z: 1400-
800-
600-
‘OOj 200
0
.
.-
.
.
.
m 31) 2 9 ZB 2 1 0
.
-
.
u
.
24
.
u
.
.
.
2 2 21 20 I-
.
IS
.
lY
.
.
1 8 I?
.
IS
.
.
.
I?) 14 1 3
*s.o
theoretical response in a patient from a given number of platelet concentrates, the procedure should be reversed. Figure 2 is used in like manner to determine responses to Factor VIII concentrate or cryoprecipitate. Again the body surface area or plasma volume are determined, after which the desired treatment line is selected. For convenience we also have included on this graph selected plasma volumes for males to simplify the use. The theoretical number of Factor VIII units needed is read from the ordinate. If cryoprecipitate is used, the center column indicates the approximate number of cryoprecipitate bags which should be used, based on a theoretical content of 90 Factor VIII units per bag. This amount is slightly less than that required by the BOB (40 units per 100 mi
.
12
.
II
.
: : : : I LO 09 08 o r 06
1-
. I
starting p l a ~ r n a ) ,but ~ represents a rather good average with a slight safety factor. We hope that these curves will further simplify the use of these blood components and will encourage physicians to compute the response of their patients in a more quantitative manner. References Myhre, B. A,, Ed.: Blood Component Therapy, 2nd ed. American Association of Blood Banks, 1975. 2. Federal Register 40:4380, 1975. 3. Federal Register 40:41799, 1975. I.
Byron A. Myhre, M.D., Ph.D., Harbor General Hospital Campus, 1000 West Carson St., Torrance, California 90509. Y. Nakasako, M.D., Harbor General Hospital Campus, Torrance, California, 90509.
